As the prevalence of human immunodeficiency virus (HIV) infection increases, dentist may expect more of their patients to be HIV positive (HIV +). Tooth extraction is common for HIV+ patients. While the general consensus has been that HIV+ patients can undergo tooth extraction without an increased risk of complications, this opinion is based on anecdotal observation. Our preliminary data-(n=145 patients), however, suggest that HIV+ patients are at a substantially increased risk of postextraction complications. Despite the frequency of tooth extraction, little data exist to determine if HIV+ patients have an added, unique risk of developing complications following tooth extraction. Given the increased need for tooth extraction in HIV+ patients and the elevated risk of postextraction complications in immunosuppressed patients, we hypothesize that HIV+ patients have an increased postextraction complication rate compared to HIV- patients. To test this hypothesis we propose a prospective cohort study with the following specific aims: 1) to compare the postextraction complication rate between HIV+ and HIV- patients, 2) to describe the type and frequency of postextraction complications, 3) to describe the management of postextraction complications, and 4) identify risk factors associated with postextraction complications. To achieve our aims we propose using a prospective cohort study that will enroll patients over an 18 month period. The cohort will consist of 165 patients who require the extraction of one or more teeth. The predictor variable will be HIV status (HIV+ or HIV-) and the outcome variable will be postoperative complication. Assessment of study variables will be made preoperatively and at three times over a 3 week period. The sample size is adequate to detect a difference of 15% in postextraction complication rate between the two groups with a power of 80%. This is the first study designed to enroll a large cohort of HIV+ and HIV= patients to assess the consequences of tooth extraction for HIV+ patients. Knowledge obtained will permit dentists to: 1) adequately counsel patients regarding treatment, and 2) identify preoperative risk factors for complications. If this study demonstrates that HIV+ patients do have an increased risk of postextraction complications, future studies will be directed towards a better understanding of the cellular/immune defects associated with these complications.